xfs: don't block in busy flushing when freeing extents

[linux-2.6-block.git] / fs / xfs / libxfs / xfs_alloc.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#ifndef __XFS_ALLOC_H__
#define	__XFS_ALLOC_H__

struct xfs_buf;
struct xfs_btree_cur;
struct xfs_mount;
struct xfs_perag;
struct xfs_trans;

extern struct workqueue_struct *xfs_alloc_wq;

unsigned int xfs_agfl_size(struct xfs_mount *mp);

/*
 * Flags for xfs_alloc_fix_freelist.
 */
#define	XFS_ALLOC_FLAG_TRYLOCK	(1U << 0)  /* use trylock for buffer locking */
#define	XFS_ALLOC_FLAG_FREEING	(1U << 1)  /* indicate caller is freeing extents*/
#define	XFS_ALLOC_FLAG_NORMAP	(1U << 2)  /* don't modify the rmapbt */
#define	XFS_ALLOC_FLAG_NOSHRINK	(1U << 3)  /* don't shrink the freelist */
#define	XFS_ALLOC_FLAG_CHECK	(1U << 4)  /* test only, don't modify args */
#define	XFS_ALLOC_FLAG_TRYFLUSH	(1U << 5)  /* don't wait in busy extent flush */

/*
 * Argument structure for xfs_alloc routines.
 * This is turned into a structure to avoid having 20 arguments passed
 * down several levels of the stack.
 */
typedef struct xfs_alloc_arg {
	struct xfs_trans *tp;		/* transaction pointer */
	struct xfs_mount *mp;		/* file system mount point */
	struct xfs_buf	*agbp;		/* buffer for a.g. freelist header */
	struct xfs_perag *pag;		/* per-ag struct for this agno */
	xfs_fsblock_t	fsbno;		/* file system block number */
	xfs_agnumber_t	agno;		/* allocation group number */
	xfs_agblock_t	agbno;		/* allocation group-relative block # */
	xfs_extlen_t	minlen;		/* minimum size of extent */
	xfs_extlen_t	maxlen;		/* maximum size of extent */
	xfs_extlen_t	mod;		/* mod value for extent size */
	xfs_extlen_t	prod;		/* prod value for extent size */
	xfs_extlen_t	minleft;	/* min blocks must be left after us */
	xfs_extlen_t	total;		/* total blocks needed in xaction */
	xfs_extlen_t	alignment;	/* align answer to multiple of this */
	xfs_extlen_t	minalignslop;	/* slop for minlen+alignment calcs */
	xfs_agblock_t	min_agbno;	/* set an agbno range for NEAR allocs */
	xfs_agblock_t	max_agbno;	/* ... */
	xfs_extlen_t	len;		/* output: actual size of extent */
	int		datatype;	/* mask defining data type treatment */
	char		wasdel;		/* set if allocation was prev delayed */
	char		wasfromfl;	/* set if allocation is from freelist */
	struct xfs_owner_info	oinfo;	/* owner of blocks being allocated */
	enum xfs_ag_resv_type	resv;	/* block reservation to use */
#ifdef DEBUG
	bool		alloc_minlen_only; /* allocate exact minlen extent */
#endif
} xfs_alloc_arg_t;

/*
 * Defines for datatype
 */
#define XFS_ALLOC_USERDATA		(1 << 0)/* allocation is for user data*/
#define XFS_ALLOC_INITIAL_USER_DATA	(1 << 1)/* special case start of file */
#define XFS_ALLOC_NOBUSY		(1 << 2)/* Busy extents not allowed */

/* freespace limit calculations */
unsigned int xfs_alloc_set_aside(struct xfs_mount *mp);
unsigned int xfs_alloc_ag_max_usable(struct xfs_mount *mp);

xfs_extlen_t xfs_alloc_longest_free_extent(struct xfs_perag *pag,
		xfs_extlen_t need, xfs_extlen_t reserved);
unsigned int xfs_alloc_min_freelist(struct xfs_mount *mp,
		struct xfs_perag *pag);
int xfs_alloc_get_freelist(struct xfs_perag *pag, struct xfs_trans *tp,
		struct xfs_buf *agfbp, xfs_agblock_t *bnop, int	 btreeblk);
int xfs_alloc_put_freelist(struct xfs_perag *pag, struct xfs_trans *tp,
		struct xfs_buf *agfbp, struct xfs_buf *agflbp,
		xfs_agblock_t bno, int btreeblk);

/*
 * Compute and fill in value of m_alloc_maxlevels.
 */
void
xfs_alloc_compute_maxlevels(
	struct xfs_mount	*mp);	/* file system mount structure */

/*
 * Log the given fields from the agf structure.
 */
void
xfs_alloc_log_agf(
	struct xfs_trans *tp,	/* transaction pointer */
	struct xfs_buf	*bp,	/* buffer for a.g. freelist header */
	uint32_t	fields);/* mask of fields to be logged (XFS_AGF_...) */

/*
 * Allocate an extent anywhere in the specific AG given. If there is no
 * space matching the requirements in that AG, then the allocation will fail.
 */
int xfs_alloc_vextent_this_ag(struct xfs_alloc_arg *args, xfs_agnumber_t agno);

/*
 * Allocate an extent as close to the target as possible. If there are not
 * viable candidates in the AG, then fail the allocation.
 */
int xfs_alloc_vextent_near_bno(struct xfs_alloc_arg *args,
		xfs_fsblock_t target);

/*
 * Allocate an extent exactly at the target given. If this is not possible
 * then the allocation fails.
 */
int xfs_alloc_vextent_exact_bno(struct xfs_alloc_arg *args,
		xfs_fsblock_t target);

/*
 * Best effort full filesystem allocation scan.
 *
 * Locality aware allocation will be attempted in the initial AG, but on failure
 * non-localised attempts will be made. The AGs are constrained by previous
 * allocations in the current transaction. Two passes will be made - the first
 * non-blocking, the second blocking.
 */
int xfs_alloc_vextent_start_ag(struct xfs_alloc_arg *args,
		xfs_fsblock_t target);

/*
 * Iterate from the AG indicated from args->fsbno through to the end of the
 * filesystem attempting blocking allocation. This is for use in last
 * resort allocation attempts when everything else has failed.
 */
int xfs_alloc_vextent_first_ag(struct xfs_alloc_arg *args,
		xfs_fsblock_t target);

/*
 * Free an extent.
 */
int				/* error */
__xfs_free_extent(
	struct xfs_trans	*tp,	/* transaction pointer */
	struct xfs_perag	*pag,
	xfs_agblock_t		agbno,
	xfs_extlen_t		len,	/* length of extent */
	const struct xfs_owner_info	*oinfo,	/* extent owner */
	enum xfs_ag_resv_type	type,	/* block reservation type */
	bool			skip_discard);

static inline int
xfs_free_extent(
	struct xfs_trans	*tp,
	struct xfs_perag	*pag,
	xfs_agblock_t		agbno,
	xfs_extlen_t		len,
	const struct xfs_owner_info	*oinfo,
	enum xfs_ag_resv_type	type)
{
	return __xfs_free_extent(tp, pag, agbno, len, oinfo, type, false);
}

int				/* error */
xfs_alloc_lookup_le(
	struct xfs_btree_cur	*cur,	/* btree cursor */
	xfs_agblock_t		bno,	/* starting block of extent */
	xfs_extlen_t		len,	/* length of extent */
	int			*stat);	/* success/failure */

int				/* error */
xfs_alloc_lookup_ge(
	struct xfs_btree_cur	*cur,	/* btree cursor */
	xfs_agblock_t		bno,	/* starting block of extent */
	xfs_extlen_t		len,	/* length of extent */
	int			*stat);	/* success/failure */

int					/* error */
xfs_alloc_get_rec(
	struct xfs_btree_cur	*cur,	/* btree cursor */
	xfs_agblock_t		*bno,	/* output: starting block of extent */
	xfs_extlen_t		*len,	/* output: length of extent */
	int			*stat);	/* output: success/failure */

union xfs_btree_rec;
void xfs_alloc_btrec_to_irec(const union xfs_btree_rec *rec,
		struct xfs_alloc_rec_incore *irec);
xfs_failaddr_t xfs_alloc_check_irec(struct xfs_btree_cur *cur,
		const struct xfs_alloc_rec_incore *irec);

int xfs_read_agf(struct xfs_perag *pag, struct xfs_trans *tp, int flags,
		struct xfs_buf **agfbpp);
int xfs_alloc_read_agf(struct xfs_perag *pag, struct xfs_trans *tp, int flags,
		struct xfs_buf **agfbpp);
int xfs_alloc_read_agfl(struct xfs_perag *pag, struct xfs_trans *tp,
		struct xfs_buf **bpp);
int xfs_free_agfl_block(struct xfs_trans *, xfs_agnumber_t, xfs_agblock_t,
			struct xfs_buf *, struct xfs_owner_info *);
int xfs_alloc_fix_freelist(struct xfs_alloc_arg *args, uint32_t alloc_flags);
int xfs_free_extent_fix_freelist(struct xfs_trans *tp, struct xfs_perag *pag,
		struct xfs_buf **agbp);

xfs_extlen_t xfs_prealloc_blocks(struct xfs_mount *mp);

typedef int (*xfs_alloc_query_range_fn)(
	struct xfs_btree_cur			*cur,
	const struct xfs_alloc_rec_incore	*rec,
	void					*priv);

int xfs_alloc_query_range(struct xfs_btree_cur *cur,
		const struct xfs_alloc_rec_incore *low_rec,
		const struct xfs_alloc_rec_incore *high_rec,
		xfs_alloc_query_range_fn fn, void *priv);
int xfs_alloc_query_all(struct xfs_btree_cur *cur, xfs_alloc_query_range_fn fn,
		void *priv);

int xfs_alloc_has_records(struct xfs_btree_cur *cur, xfs_agblock_t bno,
		xfs_extlen_t len, enum xbtree_recpacking *outcome);

typedef int (*xfs_agfl_walk_fn)(struct xfs_mount *mp, xfs_agblock_t bno,
		void *priv);
int xfs_agfl_walk(struct xfs_mount *mp, struct xfs_agf *agf,
		struct xfs_buf *agflbp, xfs_agfl_walk_fn walk_fn, void *priv);

static inline __be32 *
xfs_buf_to_agfl_bno(
	struct xfs_buf		*bp)
{
	if (xfs_has_crc(bp->b_mount))
		return bp->b_addr + sizeof(struct xfs_agfl);
	return bp->b_addr;
}

int __xfs_free_extent_later(struct xfs_trans *tp, xfs_fsblock_t bno,
		xfs_filblks_t len, const struct xfs_owner_info *oinfo,
		enum xfs_ag_resv_type type, bool skip_discard);

/*
 * List of extents to be free "later".
 * The list is kept sorted on xbf_startblock.
 */
struct xfs_extent_free_item {
	struct list_head	xefi_list;
	uint64_t		xefi_owner;
	xfs_fsblock_t		xefi_startblock;/* starting fs block number */
	xfs_extlen_t		xefi_blockcount;/* number of blocks in extent */
	struct xfs_perag	*xefi_pag;
	unsigned int		xefi_flags;
	enum xfs_ag_resv_type	xefi_agresv;
};

void xfs_extent_free_get_group(struct xfs_mount *mp,
		struct xfs_extent_free_item *xefi);

#define XFS_EFI_SKIP_DISCARD	(1U << 0) /* don't issue discard */
#define XFS_EFI_ATTR_FORK	(1U << 1) /* freeing attr fork block */
#define XFS_EFI_BMBT_BLOCK	(1U << 2) /* freeing bmap btree block */

static inline int
xfs_free_extent_later(
	struct xfs_trans		*tp,
	xfs_fsblock_t			bno,
	xfs_filblks_t			len,
	const struct xfs_owner_info	*oinfo,
	enum xfs_ag_resv_type		type)
{
	return __xfs_free_extent_later(tp, bno, len, oinfo, type, false);
}


extern struct kmem_cache	*xfs_extfree_item_cache;

int __init xfs_extfree_intent_init_cache(void);
void xfs_extfree_intent_destroy_cache(void);

#endif	/* __XFS_ALLOC_H__ */